Electrical outlet



Nov. 28, 1950 B. B. BIERCE 2,532,219

ELECTRICAL OUTLET Filed July l, 1946 Patented Nov. 28, 195() ELECTRICALOUTLET Burton B. Bierce, Pewaukee.- Wis., assigner of one-half to ElwinA. Andrus, Milwaukee, Wis.

Appucafibniuly 1, i946, serial No: 680,601

This invention relates' to an electrica-l outlet of the general typeemployed for supplying current to" various electrical devices whereinatvvo prong plug makes ct'annectionl with the' outlet. l

vOne of the principal objects of the invention is to provide' an outletwhich is more safe from the meddling cf children and possible injury tochildren and others by shocks.

Another object of the invention is to provide an outlet oi standard sizewith a ground connection suitable for grounding electrical" apparatusconnected thereto,` and which is safe against acci'- dental' snorting.-

Another object is to provide Such an outlet thatl isi of simple durableconstruction and' of low cost to manufacture.

Another' object is to provide an outlet which will automatically preventdirt and moistureY from entering' the' slots for' the connecting prongs.

Another object is toprovide' an outlet having a rotary cover pla-teandin which the plate is positively and automatically returned' to aposition where' it covers the contact slots when the prongs of thep'lu'gare removed.-

Another object is to providesuchf an' outlet in whichl the prongs of theplug areA in the same plane Wheninitially inserted at the start of aplugging operation as they are atthe n'al position-V of completeinsertion into the outlet.

Other objects' and advantages appear in the following description of anvembodiment of the invention illustrated in the accompanying drawings.

In the drawings:

Figure 1- is'a perspective view of a double outlet with one of theoutlets exploded to show the parts prior to assembly;

Fig. 2 isa section through one ofthe assembled outlets takeny on thelongitudinal center line of the structure;

Figa. 3A isa-sect-ion taken transversely of Fig'. 2 acrossfthe outletonline3-3of Fig. 2;

Figiis-a section takenon line 4 4' of Fig. 2;

Fig 5 isa face'elevation-of` one of the outlets;-

Fig. 6' isa perspectivev-ievv of a plug having a thirdcentralj prong foruse with the outlet in grounding electrical apparatus; and

Fig. '7 is a section showing theiplug inserted in the socket. l

The plug constitutes the subject matter oi a copendingapplication SerialNo. 680,600, novvA abandoned, liled on even date herewith by thepresent-- inventor.

The outlet` is of standard size to llt into' any regular outlet box andto receive@ any standard plug'l connection.

The outlet comprises a suitable porcelain, phenolic resin or similar setplastic insulating base I3 having a pair of upstanding circular bodysections'Z on its front providing anfoutlet-face'at eacherid ofthe base.v

The back' f the base l has" a longitudinal first inserted in slots I3'into 2 groove 3 in which lies a metalV strip 4 extending longitudinallyof the' base and havingl its ends forine'd tc provide nang'es 5 that areadapted to be secured to the outlet box by suitable screws to hold theoutlet in place.v

The lead wires for current are con'r'iected by the corresponding screwposts t to opposite cop-'- per conductor strips i disposed along theopposite sides of the base.

The' ends or strips 'i enter the corresponding body sections 2 and areformedto provide spring contacts 8- disposed in' the correspondingslotsv 9 in the faces of the body sections'. Y

Each body section 2 has its face recessed to receive an inner circulardisc' I0' and 'an outer circular disc II which serve to cover slots 9when in normal position to prevent accidental shorting of the contactsS. n

Each` disc I@ has a pair of slots I2,I and' each disc II` has a pair ofslots I3', corresponding to the slots 9 in the body section. Both discsare mounted' for rotation in the body' section and are held in place bya central rivet I 4 which leaves the" sa'me free to turn thereon.

When in normal position, disc I`0` is turned 90 from a position ofregistry of its slots' I2 vvith the corresponding slots 9 o'f the bodysection, so that the disc' completely covers slots 9'.

When in normal position, disc Il' has its slots I3 in alignment withslots 9 of thev body section.

The discs I0 and I'I are' biased to normal position by a coil spring I5preferably of the ten-- sion type' lying in a circumferential recess I6in the disc I0 and secured at one end to` a projection I'I in the recessand' at the other end to` a pin I3 extending intol the recess from discI'I.

The projection I'i is disposed about centrally of recess I6 and thespring I5l lies in one end of the recess defined by the projection andone' end Wall. The other end of recess I6 receives a-stop I9v projectingfrom the side Wall of the body section 2;

A groove 20' is cut along the inner corner edge of disc II tofreceive'apart'of stop I9.

The' stop I9 limits the rotational movement of discsV I0 and I I and'provides for a' 90 separation` of slots I2 and |31' under the biasingaction of spring' I5.

When it is' desired to insert the prongs 2l of a` standard p1u'g'22 intoslots -9 to make contact` with contacts' 8, the ends of the prongs" 2|are e'ngager'nent' withr disc I0. 'l tother'ight 90 y unurth'e mengselregisterwiih and enter slots If2'of disc I0. The plug 22 and diScsf Ill?and: I'Ii are then turned to the left 90c to the original plane of theprongs, and the latter arethen pushedintc slots 9' to'cornplet theelec'-- trical connection.

Thefdual disc construction reduiringturnig in both? directions in ordertov complete the con'- ne'ctlon provides a protection against themed-The plug zzfand disc il are then turned'L 3 dling of children which isnot present with single discs. It provides an indication of the planefor the prongs of the plug, the outer slots I3 being preferably inalignment With slots 9.

The dual disc construction wherein the discs are biased relative to eachother by spring I5 provides for a gripping of the prongs 2i when theconnection is completed and thereby prevents accidental displacement ofthe plug and removal of the prongs. The contacts 8 are relieved of anystress from spring l5 since discs I8 and ll are floating with respect tothe body section 2.

When it is desired to remove the plug 22 it is merely pulled straightout, allowing spring l5 to bias disc l@ to the right 90 to close theslots 9 and I3. Stop i9 determines the iinal normal position for thediscs mand H.

The invention, as above described, provides a safety cover for theoutlet contacts and prevents accidental shorting of the same.

Another phase of the invention, which has particular advantage when usedwith the safety cover, lies in a ground provided for electricalapparatus. For this purpose, the rivet I4 is secured through the backstrip 4 and makes electrical contact therewith.

rlhe iront end of rivet I4 has a cylindrical recess 23 therein forreceiving a central ground prong 24 of the plug. The wire 25 connectingtheplug 22 with the electrical apparatus to be operated is preferably ofthe three wire type, one of the wires constituting a ground wireconnected to the casing of the apparatus .and to central prong 24.

The exposure of rivet I4 as a ground `terminal is not dangerous, and itsproximity to contacts 8 is also not dangerous so long as the latter arecovered by disc il).

This second phase of the invention provides a simple means for groundingelectric motor appliances and electric shavers and the like. It providesgreater safety in the operation of all electrical appliances.

The present invention is applicable to the construction of removablecover plate adapters for standard outlet sockets, as set iorth andclaimed in applicants copending application Serial No. 688,324, nowPatent No. 2,524,250, filed August 3, 1945, and which constitutes acontinuation in part hereof.

The invention may have various embodiments within the scope of theaccompanying claims.

I claim:

1. An electrical outlet comprising a body having a generally circularface with a pair of spaced slots with electrical contacts disposedtherein, a pair of generally circular discs rotatably mounted on theface of said body and each disc having a pair of slots therethroughcorresponding to the slots in said body, and means normally biasing saiddiscs rotationally relative to each other to a position in which thecorresponding slots of the discs are out of registry with each other andthe slots of the inner disc are out of registry with the slots in saidbody to provide a cover for said contacts.

2. An electrical outlet comprising a body having a generally circularface with a pair of spaced slots with electrical contacts disposedtherein, a pair of generally circular discs rotatably mounted on theface of said body and each disc having a pair of slots therethroughcorrespending to the slots in said body, means normally biasing saiddiscs rotationally relative to each other to a position in which thecorresponding slots of the discs are out of registry with each other,and means interlocking said discs and body rotationally to provide for anormal offsetting of the slots in the inner disc relative to the slotsin the body.

3. An electrical outlet comprising a body having a generally circularface with a pair of spaced slots with electrical contacts disposedtherein, a pair of generally circular discs rotatably mounted on theface of said body and each disc having a pair of slots therethroughcorresponding to the slots in said body, means normally biasing saiddiscs rotationally relative to each other to a position in which thecorresponding slots of the discs are out of registry with each other,

and means interlocking said discs and body rotationally to provide for anormal offsetting of the slots in the inner disc relative to the slotsin the body and for the slots in the outerdsc being normally disposed inalignment with those of the body.

4. An electrical outlet comprising a body having a generally circularface with a pair of spaced slots with electrical contacts disposedtherein, a

l pair of generally circular discs rotatably mounted on the face of saidbody and each disc having a pair of slots therethrough corresponding tothe slots in said body, means normally biasing said discs rotationallyrelative to each other to a position in which the corresponding slots ofthe discs are out of registry with each other and the slots of the innerdisc are out of registry with the slots in said body to provide a coverfor said contacts, and a ground connection constituting va central pinintermediate said slots and upon which said discs are rotatably mountedand which has a recess centrally thereof to re` ceive a ground prong ofa connecting plug.

5. An electrical outlet comprising a body having a generally circularface with a pair of spaced slots with electrical contacts disposedtherein, a pair of generally circular discs rotatably mounted on theface of said body and each disc having a pair of slots therethroughcorresponding to the slots in said body, means normally biasing saiddiscs rotationally relative to each other to a position in which thecorresponding slots of the discs are out of registry with each other,means interlocking said discs and body rotationally to provide for anormal offsetting of the slots in the inner disc relative to the slotsin the body and for the slots in the outer disc being normally disposedin alignment With those of the body, and a ground connectionconstituting a central pin intermediate said slots and upon which saiddiscs are rotatably mounted and which has a, recess centrally thereof toreceive a ground prong of a connecting plug.

BURTON B. BIERCE.

REFERENCES CITED The following references are of record in the file ofthis patent:

y UNITED STATES PATENTS Number Name Date 1,672,067 Labre June 5, 19281,989,693 Hubbell Feb. 5, 1935 2,154,160 Hamilton Apr. 11, 1939 FOREIGNPATENTS Number Country Date 475,824 Great Britain Nov. 26, 1937 496,966Germany Jan. 19, 1928 684,289 Germany Nov. 25, 1939

